An HcpR homologue from Desulfovibrio desulfuricans and its possible role in nitrate reduction and nitrosative stress

The Escherichia coli CRP (cAMP receptor protein), is a global regulator of transcription that modulates gene expression by activation or repression at a range of promoters in E. coli. A major function is to regulate the selection of nutrients required for growth. The anaerobic sulfate-reducing bacterium Desulfovibrio desulfuricans ATCC27774 is capable of utilizing sulfate, nitrite and nitrate as terminal electron acceptors. In the presence of both sulfate and nitrate, sulfate is reduced preferentially despite nitrate being the thermodynamically more favourable electron acceptor. Three inverted repeat sequences upstream of the D. desulfuricans ATCC27774 nap (nitrate reduction in the periplasm) operon have high levels of similarity to the consensus sequence for the E. coli CRP DNA-binding site. In other Desulfovibrio species a putative CRP homologue, HcpR [regulator of hcp (hybrid cluster protein) transcription], has a predicted regulon comprising genes involved in sulfate reduction and nitrosative stress. The presence of CRP consensus sites within the D. desulfuricans ATCC27774 nap promoter prompted a search for CRP homologues in the genomes of sulfate-reducing bacteria. This revealed the presence of a potential CRP homologue that we predict binds to CRP consensus sites such as those of the nap operon. Furthermore, we predict that much of the core HcpR regulon predicted in other Desulfovibrio species is conserved in D. desulfuricans.

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Engineering global regulator cAMP receptor protein (CRP) of E. coli for improved biobutanol tolerance

New Biotechnology ◽

10.1016/j.nbt.2014.05.1718 ◽

2014 ◽

Vol 31 ◽

pp. S46

Author(s):

Rongrong Jiang ◽

Hefang Geng ◽

Huiqing Chong

Keyword(s):

Receptor Protein ◽

Camp Receptor Protein ◽

Global Regulator ◽

E Coli ◽

Camp Receptor

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Determination of the rates of synthesis and degradation of adenosine 3′,5′-cyclic monophosphate in Escherichia coli CRP− and CRP+ strains

Canadian Journal of Biochemistry ◽

10.1139/o78-130 ◽

1978 ◽

Vol 56 (9) ◽

pp. 849-852 ◽

Cited By ~ 12

Author(s):

Ann D. E. Fraser ◽

Hiroshi Yamazaki

Keyword(s):

Escherichia Coli ◽

Receptor Protein ◽

Camp Receptor Protein ◽

Balanced Growth ◽

E Coli ◽

Cyclic Monophosphate ◽

Camp Receptor ◽

Extracellular Camp ◽

Synthesis And Degradation

We have developed a method for estimating the rates of synthesis and degradation of adenosine 3′,5′-cyclic monophosphate (cAMP) in Escherichia coli during balanced growth. Applying this method, we have found that an E. coli CRP− mutant 5333 (deficient for cAMP receptor protein) synthesizes cAMP about 25 times faster than does its CRP+ parent 1100. This accounts for the abnormally high intracellular and extracellular cAMP accumulation in 5333.

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Cyclic AMP (cAMP) and cAMP Receptor Protein Influence both Synthesis and Uptake of Extracellular Autoinducer 2 in Escherichia coli

Journal of Bacteriology ◽

10.1128/jb.187.6.2066-2076.2005 ◽

2005 ◽

Vol 187 (6) ◽

pp. 2066-2076 ◽

Cited By ~ 130

Author(s):

Liang Wang ◽

Yoshifumi Hashimoto ◽

Chen-Yu Tsao ◽

James J. Valdes ◽

William E. Bentley

Keyword(s):

Escherichia Coli ◽

Cyclic Amp ◽

Carbon Sources ◽

Cell Communication ◽

Receptor Protein ◽

Upstream Region ◽

E Coli ◽

Autoinducer 2 ◽

Serovar Typhimurium ◽

Camp Receptor

ABSTRACT Bacterial autoinducer 2 (AI-2) is proposed to be an interspecies mediator of cell-cell communication that enables cells to operate at the multicellular level. Many environmental stimuli have been shown to affect the extracellular AI-2 levels, carbon sources being among the most important. In this report, we show that both AI-2 synthesis and uptake in Escherichia coli are subject to catabolite repression through the cyclic AMP (cAMP)-CRP complex, which directly stimulates transcription of the lsr (for “luxS regulated”) operon and indirectly represses luxS expression. Specifically, cAMP-CRP is shown to bind to a CRP binding site located in the upstream region of the lsr promoter and works with the LsrR repressor to regulate AI-2 uptake. The functions of the lsr operon and its regulators, LsrR and LsrK, previously reported in Salmonella enterica serovar Typhimurium, are confirmed here for E. coli. The elucidation of cAMP-CRP involvement in E. coli autoinduction impacts many areas, including the growth of E. coli in fermentation processes.

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Preferential Reduction of the Thermodynamically Less Favorable Electron Acceptor, Sulfate, by a Nitrate-Reducing Strain of the Sulfate-Reducing Bacterium Desulfovibrio desulfuricans 27774

Journal of Bacteriology ◽

10.1128/jb.01171-08 ◽

2008 ◽

Vol 191 (3) ◽

pp. 882-889 ◽

Cited By ~ 27

Author(s):

Angeliki Marietou ◽

Lesley Griffiths ◽

Jeff Cole

Keyword(s):

Transcription Start Site ◽

Electron Acceptor ◽

Nitrate Reduction ◽

Desulfovibrio Desulfuricans ◽

Start Codon ◽

Start Site ◽

Transcription Start ◽

Sulfate Reducing ◽

Reverse Transcription Pcr ◽

Nitrate Induction

ABSTRACT Desulfovibrio desulfuricans strain 27774 is one of a relative small group of sulfate-reducing bacteria that can also grow with nitrate as an alternative electron acceptor, but how nitrate reduction is regulated in any sulfate-reducing bacterium is controversial. Strain 27774 grew more rapidly and to higher yields of biomass with nitrate than with sulfate or nitrite as the only electron acceptor. In the presence of both sulfate and nitrate, sulfate was used preferentially, even when cultures were continuously gassed with nitrogen and carbon dioxide to prevent sulfide inhibition of nitrate reduction. The napC transcription start site was identified 112 bases upstream of the first base of the translation start codon. Transcripts initiated at the napC promoter that were extended across the napM-napA boundary were detected by reverse transcription-PCR, confirming that the six nap genes can be cotranscribed as a single operon. Real-time PCR experiments confirmed that nap operon expression is regulated at the level of mRNA transcription by at least two mechanisms: nitrate induction and sulfate repression. We speculate that three almost perfect inverted-repeat sequences located upstream of the transcription start site might be binding sites for one or more proteins of the CRP/FNR family of transcription factors that mediate nitrate induction and sulfate repression of nitrate reduction by D. desulfuricans.

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Regulation of ytfK by cAMP-CRP Contributes to SpoT-Dependent Accumulation of (p)ppGpp in Response to Carbon Starvation YtfK Responds to Glucose Exhaustion

Frontiers in Microbiology ◽

10.3389/fmicb.2021.775164 ◽

2021 ◽

Vol 12 ◽

Author(s):

Laura Meyer ◽

Elsa Germain ◽

Etienne Maisonneuve

Keyword(s):

Escherichia Coli ◽

Cyclic Amp ◽

Catabolite Repression ◽

Stringent Response ◽

Receptor Protein ◽

Glucose Starvation ◽

Camp Receptor Protein ◽

E Coli ◽

Camp Receptor ◽

Glucose Availability

Guanosine penta- or tetraphosphate (known as (p)ppGpp) serves as second messenger to respond to nutrient downshift and other environmental stresses, a phenomenon called stringent response. Accumulation of (p)ppGpp promotes the coordinated inhibition of macromolecule synthesis, as well as the activation of stress response pathways to cope and adapt to harmful conditions. In Escherichia coli, the (p)ppGpp level is tightly regulated by two enzymes, the (p)ppGpp synthetase RelA and the bifunctional synthetase/hydrolase SpoT. We recently identified the small protein YtfK as a key regulator of SpoT-mediated activation of stringent response in E. coli. Here, we further characterized the regulation of ytfK. We observed that ytfK is subjected to catabolite repression and is positively regulated by the cyclic AMP (cAMP)-cAMP receptor protein (CRP) complex. Importantly, YtfK contributes to SpoT-dependent accumulation of (p)ppGpp and cell survival in response to glucose starvation. Therefore, regulation of ytfK by the cAMP-CRP appears important to adjust (p)ppGpp level and coordinate cellular metabolism in response to glucose availability.

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